On the mobility of carbon-supported platinum nanoparticles towards unveiling cathode degradation in water electrolysis

High resolution transmission electron microscopy and electronic structure theory investigation of platinum nanoparticles on carbon black

“…Indeed, with the availability of correction schemes for dispersion interactions, 30,31 in one of our previous studies, 21 we showed that there is a transition between an interaction with covalent character for smaller clusters and a dispersiondominated interaction for larger particles on the graphene basal plane. The same observations were made in the studies of Ramos-Sanchez and Balbuena 22 and Verga et al 19 These conclusions are in agreement with experimental observations of rather mobile nanoparticles on graphene basal planes, 32 as dispersion interactions are inherently non-directional.…”

Supported ionic liquid phase-boosted highly active and durable electrocatalysts towards hydrogen evolution reaction in acidic electrolyte

“…In order to gain more insight into the reason for the improved HER stability of IL@Pt/C electrocatalysts, identical-location TEM (IL-TEM) technique was employed to probe the structural change on a microscopic scale. To the best of our knowledge, different from its intensive application in oxygen reduction reaction (ORR), there are only very few IL-TEM measurements performed in HER conditions [68], mainly because the HER stability test tends to yield hydrogen bubbles that are difficult to detach from the TEM grids, which in turn blocks the contact of electrolyte and electrocatalyst for subsequent reduction of proton. In order to overcome this issue, the IL-TEM test in this study was performed before and after accelerated degradation test (ADT) which consisted of 2000 CV cycles between À0.1 V and 0.0 V vs. RHE with a scanning speed of 50 mV/s in 0.5 M H 2 SO 4 .…”

Nanocatalyst Design for Long‐Term Operation of Proton/Anion Exchange Membrane Water Electrolysis

“…Also, the in situ TEM analysis revealed the agglomeration of Pt nanoparticles (NPs), which was induced by gas bubbles, during HER. [ 33 ] These results indicate that severe degradation of catalysts proceeds through agglomeration and dissolution at the cathode during long‐term HER, even though the catalysts are based on the stable noble metals.…”

“…Also, gas bubbles promote the catalyst migration, agglomeration, and detachment significantly during the WE operation. [ 33 ] Since water‐splitting occurs on fully wet surfaces (i.e., Wenzel state) and gas bubbles dry the electrode surface partially or fully (i.e., Cassie state), gas bubble management through surface wettability control has been the pivotal issue to the design of a stable WE system. [ 96 ] To achieve wettability controllable architectures, biomimetic structures, similar to lotus leaves, roses, petals, and fish scales, have been widely developed.…”